Question

 sin( a-П) +tg(a-п) +сos (a+3п2)= tga

Answer 1

sin(α-π)+tg(α-π)+cos(α+3π/2)=tga;

sinα-sin(π-α)-tg(π-α)=sinα-sinα+tgα=tgα;

 

tgα=tgα - доказано.